Recovery op tolylene diisocyanate in rising film evaporators



DEFENSIVE PUBLICATION UNITED STATES PATENT OFFICE Published at therequest of the applicant or owner in accordance with the Notice of Dec,16, 1969, 869 O.G. 687. The abstracts of Defensive Publicationapplications are identified by distinctly numbered series and arearranged chronologically. The heading of each abstract indicates thenumber of pages of specification including claims and sheets of drawingscontained in the application as originally filed. The files of theseapplications are available to the public for inspection and reproductionmay be purchased for 30 cents a sheet.

Defensive Publication applications have not been examined as to themerits of alleged invention. The Patent Ofice makes no assertion as tothe novelty of the disclosed subject matter.

PUBLISHED JUNE 16, 1970 T875,017 RECOVERY OF TOLYLENE DHSOCYANATE INRISING FILM EVAPORATORS Francis V. Bailor, Jr., 43 Henderson Road, Apt.8D, Newark, Del. 19711, and John L. Littlefield, 103 Wentworth Drive,Claymont, Del. 19703 Filed Oct. 30, 1969, Ser. No. 872,587 Int. Cl. B01d3/04 US. Cl. 20373 1 Sheet Drawing. 12 Pages Specification A process forthe recovery of tolylene diisocyanate (TDI) from the crude reaction massproduced by the phosgenation of tolylene diamine which consistsessentially of (1) distilling said crude reaction mass to produce TDIvapor and a viscous tarry distillation heel containing 50-80% TDI and20-50% non-volatile residue, (2) passing said distillation heel througha heated tube about 4-20 feet in length and having an exit pressure of05-15 mm. Hg to produce additional TDI vapor and a liquid efiluent and(3) condensing and recovering said TDI vapor from steps (1) and (2).

June 1, 1970 F. v. BAILOR, JR; ETAL 375017 RECOVER Y 0F TOLYLENEDIISOCYANATE IN'RISING FILM EVAPORATORS Filed Oct. 30, 1969 INVENTORSFRANCIS v. BAILOR,JR JOHN L. LITTLEFIELD ATTORNEY

